The manufacturing of very high quality magnetic materials encounters problems which impair the material quality after solidification, among which can be mentioned the influence of the walls and convection phenomena in the liquid phase. These problems are inherent in the coexistence of, on the one hand, composition, temperature or density gradients and, on the other hand, the gravity field. Sedimentation and stratification phenomena also occur in liquids including solid suspensions, or non-miscible liquid suspensions; the heaviest suspensions move downwardly. These various effects are responsible for the lack of homogeneity in composition and defects in the magnetic material after solidification.
To overcome these various problems, it has been proposed to manufacture materials in satellites or during free fall in order to obtain a zero gravity or microgravity condition. But this implies very powerful and expensive means.